<template>
    <!-- 商品分类导航 -->
    <div class="type-nav">
        <div class="container">
            <div @mouseleave="leaveIndex" @mouseenter="enterShow">
                <h2 class="all" @mouseleave="leaveIndex">全部商品分类</h2>
                <!-- 过渡动画 -->
                <transition name="animate__animated animate__bounce" :appear="false" enter-active-class="animate__fadeIn"
                    leave-active-class="animate__fadeOut">
                    <!-- 三级联动 -->
                    <div class="sort" v-show="show" @mouseenter="enterShow">
                        <div class="all-sort-list2" @click="goSearch">
                            <div class="item" v-for="(c1, index) in categoryList" :key="c1.categoryId"
                                :class="{ cur: currentIndex == index }">
                                <!-- :class="{ cur: currentIndex == index }动态样式，当currentIndex的样式==index时候加上样式 -->
                                <h3 @mouseenter="changeIndex(index)">
                                    <a :data-categoryName="c1.categoryName" :data-category1Id="c1.categoryId">{{
                                        c1.categoryName }}</a>
                                    <!-- <router-link to="/search">{{ c1.categoryName }}</router-link> -->
                                </h3>
                                <div class="item-list clearfix"
                                    :style="{ display: currentIndex == index ? 'block' : 'none' }">
                                    <div class="subitem" v-for="(c2, index) in c1.categoryChild" :key="c2.categoryId">
                                        <dl class="fore">
                                            <dt>
                                                <a :data-categoryName="c2.categoryName" :data-category2Id="c2.categoryId">{{
                                                    c2.categoryName }}</a>
                                                <!-- <router-link to="/search">{{ c2.categoryName }}</router-link> -->
                                            </dt>
                                            <dd>
                                                <em v-for="(c3, index) in c2.categoryChild" :key="c3.categoryId">
                                                    <a :data-categoryName="c3.categoryName"
                                                        :data-category3Id="c3.categoryId">{{ c3.categoryName }}</a>
                                                    <!-- <router-link to="/search">{{ c3.categoryName }}</router-link> -->
                                                </em>
                                            </dd>
                                        </dl>
                                    </div>
                                </div>
                            </div>
                        </div>
                    </div>
                </transition>
            </div>
            <nav class="nav">
                <a href="###">服装城</a>
                <a href="###">美妆馆</a>
                <a href="###">尚品汇超市</a>
                <a href="###">全球购</a>
                <a href="###">闪购</a>
                <a href="###">团购</a>和
                <a href="###">有趣</a>
                <a href="###">秒杀</a>
            </nav>
        </div>
    </div>
</template>

<script>
import { mapState, mapActions } from "vuex";
import "animate.css";
//最好按需加载
import throttle from "lodash/throttle";
export default {
    name: "TypeNav",
    //组件挂载完毕，可以向服务器发请求
    data() {
        return {
            //存储用户鼠标移到那个栏目
            currentIndex: -1,
            show: true,
        };
    },
    methods: {
        //一级分类鼠标进入修改响应式数据currentIndex
        // changeIndex(index) {
        //     this.currentIndex = index
        // },
        //通过lodash实现节流
        changeIndex: throttle(function (index) {
            this.currentIndex = index;
        }, 50),

        //进行三级联动路由跳转
        goSearch() {
            //最好的解决方案：编程式导航+事件委派
            //利用事件委派存在一些问题：1：点击一定是a标签? 2：如何获取参数【1、2、3级分类的产品的名字、id】

            //第一个问题：把子节点当中a标签，我加上自定义属性data-categoryName,其余的子节点是没有的
            let element = event.target;
            console.log(element);
            //获取到当前出发这个事件的节点【h3、a、dt、dl】, 需要带有data-categoryname; 这样节点【一定是a标签】
            //节点有一个属性dataset属性，可以获取节点的自定义属性与属性值
            //如果标签身上拥有categoryname-一定是a标签
            let { categoryname, category1id, category2id, category3id } =
                element.dataset;
            if (categoryname) {
                //如果有categoryname说明是q标签
                //整理路由跳转的参数
                let location = { name: "search" };
                // this.$router.push({ name: "search", query: { categoryName: 'xxx', 2id: 'xx'} })
                let query = { categoryName: categoryname }; //categoryname是浏览器解构出来的，所以是小写
                //一级分类、二级分类、三级分类的a标签
                if (category1id) {
                    query.category1Id = category1id;
                } else if (category2id) {
                    query.category2Id = category2id;
                } else {
                    query.category3Id = category3id;
                }
                location.query = query;
                //判断：如果路由跳转的时候，带有params参数，捎带脚传递过去
                if (this.$route.params) {
                    location.params = this.$route.params;
                }
                //整理完参数合并对象
                //路由跳转
                this.$router.push(location);
            }
        },

        //在Search路由里面，当鼠标移入全部商品分类,让链表显示出来
        enterShow() {
            this.show = true;
        },
        //一级分类鼠标移出
        leaveIndex() {
            this.currentIndex = -1;
            //在Search路由里面，当鼠标移出全部商品分类,让链表消失
            if (this.$route.name != "home") {
                this.show = false;
            }
        },
    },
    mounted() {
        //通知vuex发请求，获取数据，存储在vuex中
        // this.$store.dispatch('category')
        console.log(this.$store.state.home, "我是TypeNav挂载完毕");
        // this.$store.dispatch("home/category");放在这里会多次请求，所以放到App里面
        //当组件挂载完毕，让show属性变为false
        //如果不是home路由组件，就把TypeNav隐藏
        console.log(this.$route);
        if (this.$route.name !== "home") {
            this.show = false;
        }
    },
    computed: {
        //在里面的state是大仓库，里面有home search
        // ...mapState({ categoryList:(state)=>{
        //     console.log(state);
        //     return state.home.categoryList
        // } })
        ...mapState("home", ["categoryList"]),
    },
};
</script>

<style lang="less" scoped>
.type-nav {
    border-bottom: 2px solid #e1251b;

    .container {
        width: 1200px;
        margin: 0 auto;
        display: flex;
        position: relative;

        .all {
            width: 210px;
            height: 45px;
            background-color: #e1251b;
            line-height: 45px;
            text-align: center;
            color: #fff;
            font-size: 14px;
            font-weight: bold;
        }

        .nav {
            a {
                height: 45px;
                margin: 0 22px;
                line-height: 45px;
                font-size: 16px;
                color: #333;
            }
        }

        .sort {
            position: absolute;
            left: 0;
            top: 45px;
            width: 210px;
            height: 461px;
            position: absolute;
            background: #fafafa;
            z-index: 999;

            .all-sort-list2 {
                .item {
                    h3 {
                        line-height: 28px;
                        font-size: 14px;
                        font-weight: 400;
                        overflow: hidden;
                        padding: 0 20px;
                        margin: 0;

                        a {
                            color: #333;
                        }
                    }

                    .item-list {
                        display: none;
                        position: absolute;
                        width: 734px;
                        min-height: 460px;
                        background: #f7f7f7;
                        left: 210px;
                        border: 1px solid #ddd;
                        top: 0;
                        z-index: 9999 !important;

                        .subitem {
                            float: left;
                            width: 650px;
                            padding: 0 4px 0 8px;

                            dl {
                                border-top: 1px solid #eee;
                                padding: 6px 0;
                                overflow: hidden;
                                zoom: 1;

                                &.fore {
                                    border-top: 0;
                                }

                                dt {
                                    float: left;
                                    width: 54px;
                                    line-height: 22px;
                                    text-align: right;
                                    padding: 3px 6px 0 0;
                                    font-weight: 700;
                                }

                                dd {
                                    float: left;
                                    width: 415px;
                                    padding: 3px 0 0;
                                    overflow: hidden;

                                    em {
                                        float: left;
                                        height: 14px;
                                        line-height: 14px;
                                        padding: 0 8px;
                                        margin-top: 5px;
                                        border-left: 1px solid #ccc;
                                    }
                                }
                            }
                        }
                    }

                    // &:hover {
                    //     .item-list {
                    //         display: block;
                    //     }
                    // }
                }

                .cur {
                    background-color: #e1251b;
                }

                .cur2 {
                    color: #ddd;
                }
            }
        }
    }
}
</style>
